Roy Foster’s new book focuses on a group of brilliant Irish bohemians and intellectuals who were active from 1916 to 1923, though often marginalised thereafter. Their lives are fascinating, but one should be wary of overstating their centrality to ‘the revolutionary generation’.

We may disagree over how best to commemorate the First World War, but we should recognise that it fundamentally changed Ireland, creating the conditions that made possible the revolutionary events of 1916 to 1923.

Most Tans were young, unemployed, former enlisted men in the wartime military, and products of England’s urban working class. Victims of a spiralling unemployment crisis, they were attracted to Ireland by promises of upward mobility, steady work, good pay, and a comfortable pension. Since little can be determined about the nature of the constables’ prior war service, Leeson sanely suggests historians stop presuming they suffered from post-traumatic stress disorder.